pub fn new_birthday_probability(n: u32) -> f64 {
    let resut = 1.0f64;
    if n >= 365 {
        resut
    } else {
        let mut t = 1.0f64;
        for i in 1..n {
            t *= (365 - i) as f64 / 365.0;
        }
        resut - t
    }
}
